Runtime 1 ms (Top 99.73%) | Memory 40.0 MB (Top 28.38%)

Author: AnasImloul

scripts/algorithms/U/Unique Number of Occurrences/Unique Number of Occurrences.java

@@ -1,18 +1,25 @@
-// Runtime: 5 ms (Top 17.42%) | Memory: 42.1 MB (Top 47.50%)
 class Solution {
     public boolean uniqueOccurrences(int[] arr) {
+        Arrays.sort(arr);
+        HashSet<Integer> set = new HashSet<>();
 
-        var hmap = new HashMap<Integer,Integer>();
-        for(int i:arr){
-            hmap.put(i,hmap.getOrDefault(i,0)+1);
-        }
-        var arrli=new ArrayList<Integer>(hmap.keySet());
-          var set=new HashSet<Integer>();
+        int c = 1;
+        for(int i = 1; i < arr.length; i++)
+        {
+            if(arr[i] == arr[i-1]) c++;
+
+            else
+            {
+                if(set.contains(c)) return false;
 
-        for(Integer i: arrli)
-            set.add(hmap.get(i));
+                set.add(c);
+
+                c = 1;
+            }
+        }
 
-        return set.size()==arrli.size() ? true : false;
+        if(set.contains(c)) return false;
 
+        return true;
     }
 }